The review, by Mark Ellison QC, also found it could not be ruled out that corruption may have compromised the investigation into Stephen's killing in 1993.

It was one of several revelations to emerge about the Metropolitan Police's former undercover unit, the Special Demonstration Squad (SDS), in the review of the original handling of the case.

Stephen was 18 when was he was killed in a racially-motivated attack

Stephen's father, Neville Lawrence, has expressed doubts that the planned judge-led public inquiry will be able to uncover the truth.

'Complete honesty'

On Thursday, Home Secretary Theresa May told MPs the findings in the Ellison report had damaged the police and ordered the public inquiry.

The Special Demonstration Squad (SDS)

The SDS was a top secret squad within the Metropolitan Police Special Branch, and was operational from 1968 - in the wake of violent anti-Vietnam War demonstrations - to 2006

It specialised in the long-term undercover deployment of officers into a range of groups that had the potential to cause serious public disorder or other violence or injury

Officers who carried out undercover work for the SDS were given a lifetime guarantee by the Met that their identity would be protected

In his report, Mark Ellison QC said there were many examples of SDS undercover officers running great risks to themselves in order to gain very valuable intelligence

The group searched gravestones for the names of young children who would have been a similar age to provide an under cover identity

The group reportedly became known as "the hairies" because of the long hair and beards considered essential to blend in with some of the the groups being targeted

The Ellison report found an SDS "spy" had worked within the "Lawrence family camp" during the Macpherson Inquiry, conducted in the late-90s to look at the way the police had investigated the murder of Stephen.

Mr Khan said that police failings in the handling of the Stephen Lawrence case went to "the highest level" but no officer had been held to account.

"What we want now is evidence... in the open, [and for] those officers to be either rooted out or to face, as Doreen wants, criminal prosecution. And indeed, as far as she's concerned, those officers at a senior level who made mistakes or otherwise acted improperly - for their heads to roll," he said.

Mr Khan also stressed that police had not been open with the original Macpherson Inquiry and there were now "serious questions to be answered".

He added that while a judge-led inquiry would be able to order documents and witnesses, "you need to know those documents exist and those people exist who can answer questions".

'Vindicated'

"And what we want to ask Sir Bernard is, 'What do you have, have you given everything, or are you obfuscating as occurred during the Macpherson Inquiry?'"

The BBC's home editor Mark Easton said the latest revelations "mark a day of reckoning for Scotland Yard and potentially for trust in policing more generally".

In his first response to Thursday's Ellison review, Sir Bernard told the Evening Standard it was "a devastating report for the Metropolitan Police and one of the worst days that I have seen as a police officer".

He said it had been "awful" to see the impact on Stephen Lawrence's family, for whom he had "enormous respect".

"I cannot rewrite history and the events of the past but I do have a responsibility to ensure the trust and the confidence of the people of London in the Met now and in the future. This will need a considered response to meet head on the concerns that have been expressed in yesterday's report," he said.

On Thursday, Mr Lawrence told BBC Newsnight he had felt "devastated" by the revelations.

Stephen Lawrence murder

Stephen Lawrence was murdered in south-east London in 1993

Black teenager Stephen Lawrence, 18, was stabbed to death in an unprovoked attack by a gang of white youths as he waited at a bus stop in Eltham, south-east London, in April 1993.

A number of suspects were identified soon after the attack but it took more than 18 years to bring his killers to justice.

Several attempts to prosecute the suspects, including a private prosecution by the family, failed owing to unreliable or insufficient evidence.

In 1997, then Home Secretary Jack Straw ordered a public inquiry into the killing and its aftermath after concerns about the way the police had handled the case.

Sir William Macpherson, a retired High Court judge, led the inquiry. He accused the police of institutional racism and found a number of failings in how they had investigated the murder.

In January 2012, Gary Dobson and David Norris were found guilty of the murder by an Old Bailey jury after a review of the forensic evidence.

"To hear this being said on TV so the wider world could hear, I was vindicated.... if people had listened to us earlier on maybe things would have been different.

"From what happened with the Macpherson Inquiry, I'm very, very wary about what's going to happen now."

'Miscarriages of justice'

Stephen, a black teenager, was 18 when he was stabbed to death in an unprovoked attack by a gang of white youths in Eltham, south-east London, in April 1993.

However, it was not until 2012 that Gary Dobson and David Norris were found guilty of murdering him and sentenced to minimum terms of 15 years and two months and 14 years and three months respectively.

Mrs May said she had commissioned Mr Ellison, and the Crown Prosecution Service and attorney general, to conduct a further review into cases involving the SDS - a top secret Met police squad that was operational until 2006.

She said it was vital to establish whether there had been "miscarriages of justice" in relation to past criminal proceedings involving SDS officers.

Elsewhere, the Ellison review also found that the Met's own hard copy records of a broad investigation into possible corruption had been subject to a "mass shredding" in 2003.

The "chaotic state" of Met Police records meant a public inquiry might have "limited" potential to find out more information, it warned.